#!/bin/bash
set -euo pipefail

#############################################################################
# Portainer Stack Updater (Automation-Only)
#
# Updates Portainer stacks via REST API using local YAML files.
# Credentials stored in .env file (gitignored).
#
# Usage:
#   ./update-stack.sh <stack-name.yml>
#
# Example:
#   ./update-stack.sh open-webui.yml
#############################################################################

SCRIPT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
TOKEN_FILE="$SCRIPT_DIR/.portainer-token"
ENV_FILE="$SCRIPT_DIR/.env"

# Colors for output
RED='\033[0;31m'
GREEN='\033[0;32m'
BLUE='\033[0;34m'
NC='\033[0m' # No Color

log_info() { echo -e "${BLUE}[INFO]${NC} $1"; }
log_success() { echo -e "${GREEN}[SUCCESS]${NC} $1"; }
log_error() { echo -e "${RED}[ERROR]${NC} $1"; }

# Load credentials from .env
if [ ! -f "$ENV_FILE" ]; then
    log_error ".env file not found at $ENV_FILE"
    exit 1
fi

source "$ENV_FILE"

if [ -z "${PORTAINER_USERNAME:-}" ] || [ -z "${PORTAINER_PASSWORD:-}" ]; then
    log_error "PORTAINER_USERNAME and PORTAINER_PASSWORD must be set in .env file"
    exit 1
fi

PORTAINER_URL="${PORTAINER_URL:-http://localhost:8080}"

#############################################################################
# Authentication
#############################################################################

authenticate() {
    log_info "Authenticating with Portainer..."

    local response
    response=$(curl -s -X POST "$PORTAINER_URL/api/auth" \
        -H "Content-Type: application/json" \
        -d "{\"username\":\"$PORTAINER_USERNAME\",\"password\":\"$PORTAINER_PASSWORD\"}" \
        2>&1)

    if [ $? -ne 0 ]; then
        log_error "Failed to connect to Portainer at $PORTAINER_URL"
        exit 1
    fi

    # Extract token
    local token
    token=$(echo "$response" | python3 -c "import sys, json; print(json.load(sys.stdin)['jwt'])" 2>/dev/null)

    if [ -z "$token" ]; then
        log_error "Failed to authenticate. Check credentials in .env file."
        exit 1
    fi

    # Save token
    echo "$token" > "$TOKEN_FILE"
    chmod 600 "$TOKEN_FILE"

    log_success "Authentication successful"
    echo "$token"
}

get_token() {
    if [ -f "$TOKEN_FILE" ]; then
        cat "$TOKEN_FILE"
    else
        authenticate
    fi
}

#############################################################################
# Stack Operations
#############################################################################

get_endpoint_id() {
    local token="$1"

    local response
    response=$(curl -s -X GET "$PORTAINER_URL/api/endpoints" \
        -H "Authorization: Bearer $token" 2>&1)

    if [ $? -ne 0 ]; then
        log_error "Failed to get endpoints"
        return 1
    fi

    # Get first endpoint (local docker)
    local endpoint_id
    endpoint_id=$(echo "$response" | python3 -c "import sys, json; print(json.load(sys.stdin)[0]['Id'])" 2>/dev/null)

    if [ -z "$endpoint_id" ]; then
        log_error "No endpoints found"
        return 1
    fi

    echo "$endpoint_id"
}

get_stack_id() {
    local token="$1"
    local stack_name="$2"

    local response
    response=$(curl -s -X GET "$PORTAINER_URL/api/stacks" \
        -H "Authorization: Bearer $token" 2>&1)

    if [ $? -ne 0 ]; then
        log_error "Failed to get stacks"
        return 1
    fi

    # Find stack by name
    local stack_id
    stack_id=$(echo "$response" | python3 -c "
import sys, json
stacks = json.load(sys.stdin)
for stack in stacks:
    if stack['Name'] == '$stack_name':
        print(stack['Id'])
        break
" 2>/dev/null)

    echo "$stack_id"
}

update_stack() {
    local token="$1"
    local stack_id="$2"
    local endpoint_id="$3"
    local yaml_content="$4"

    log_info "Updating stack ID $stack_id..."

    # Create JSON payload
    local payload
    payload=$(python3 -c "
import json, sys
data = {
    'stackFileContent': '''$yaml_content''',
    'prune': False,
    'pullImage': False
}
print(json.dumps(data))
")

    local response
    response=$(curl -s -X PUT "$PORTAINER_URL/api/stacks/$stack_id?endpointId=$endpoint_id" \
        -H "Authorization: Bearer $token" \
        -H "Content-Type: application/json" \
        -d "$payload" 2>&1)

    if [ $? -ne 0 ]; then
        log_error "Failed to update stack"
        return 1
    fi

    # Check if response contains error
    if echo "$response" | grep -q '"message"'; then
        log_error "Stack update failed: $response"
        return 1
    fi

    log_success "Stack updated successfully"
    return 0
}

#############################################################################
# Main
#############################################################################

main() {
    # Validate arguments
    if [ $# -ne 1 ]; then
        log_error "Usage: $0 <stack-file.yml>"
        log_error "Example: $0 open-webui.yml"
        exit 1
    fi

    local yaml_file="$1"
    local yaml_path

    # Support both relative and absolute paths
    if [ -f "$yaml_file" ]; then
        yaml_path="$yaml_file"
    elif [ -f "$SCRIPT_DIR/$yaml_file" ]; then
        yaml_path="$SCRIPT_DIR/$yaml_file"
    else
        log_error "Stack file not found: $yaml_file"
        exit 1
    fi

    # Extract stack name from filename (remove .yml extension)
    local stack_name
    stack_name=$(basename "$yaml_file" .yml)

    log_info "Updating stack: $stack_name"

    # Read YAML content
    local yaml_content
    yaml_content=$(cat "$yaml_path")

    # Get or create API token
    local token
    token=$(get_token)

    # Get endpoint ID (local Docker)
    local endpoint_id
    endpoint_id=$(get_endpoint_id "$token")

    if [ -z "$endpoint_id" ]; then
        log_error "Failed to get endpoint ID"
        exit 1
    fi

    # Get stack ID
    local stack_id
    stack_id=$(get_stack_id "$token" "$stack_name")

    if [ -z "$stack_id" ]; then
        log_error "Stack '$stack_name' not found in Portainer"
        exit 1
    fi

    # Update stack
    if update_stack "$token" "$stack_id" "$endpoint_id" "$yaml_content"; then
        log_success "✓ Stack '$stack_name' updated successfully"
        exit 0
    else
        log_error "Failed to update stack"
        exit 1
    fi
}

main "$@"